Why Facebook, Instagram and WhatsApp all went down

Facebook, WhatsApp and Instagram were all hit by a major outage on Monday evening (4 October).

More than 3.5 billion people worldwide use the apps, with a majority of those losing access for almost six hours.

Facebook vice president of infrastructure, Santosh Janardhan, attributed the outage to adjustments the platform made to routers that manage network traffic between its data centres.

Founder Mark Zuckerberg has apologised to users for the outage, which cost the company an estimated $6bn (£4.4bn) as shares plummeted.